UV filter applied on CCD/CMOS (Nikon D80) ?

Hello,

First post from a DSLR newbie, please bear with me.

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma
18-200 for convenience. A friend of mine suggested I buy some Hoya
filters as well, at least a UV filter for taking photos in bright
sunshine. He insisted that I could keep it on all times as a protector
as well, it wouldn't affect the quality of the pictures in other conditions.

So I went shopping, and the seller told me the CCD sensors on modern
DSLRs were already coated with an anti-UV layer, and UV filters were
therefore useless, or recommended for film cameras only. I trusted him
and bought a simple lens protector.

I could not find any information relevant to the existence of UV-filter
coatings on CCDs. Any definite answer ?

Thank you.

Lorenzo

Lorenzo Sandini wrote:
First post from a DSLR newbie, please bear with me.

Bears are nasty animals, and if you have one with you,
you're due some real respect.

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma

This is not a microscope, it's a camera. That is not an
objective, it's the freaking *lense*! :-)

18-200 for convenience.

It's a good thing you got it for convenience, because
you don't exactly have the two highest quality lenses
that Nikon ever made... :-(

A friend of mine suggested I buy some Hoya
filters as well, at least a UV filter for taking photos in bright
sunshine.

At that point, you can begin to disregard everything he
ever says about photography. Smile, listen... and let
it all pass. Whatever a UV filter might be for, bright
sunshine isn't part of it!

He insisted that I could keep it on all times as a protector
as well, it wouldn't affect the quality of the pictures in other conditions.

Well, you _can_ keep it on at all times, and yes it will
act as a protector. Whether you need a protector for
the front of your lense is a question that will draw all
sorts of arguments both for and against. Generally, you
don't. But if you are taking pictures in a welding
shop, at the beach, or some other equally hostile place,
it might well be worth having a protective filter.

Whatever, don't kid yourself that adding another couple
of air/glass transitions isn't going to affect the
quality of your pictures. Of course... it may not
affect it enough for you to notice, so that too will
draw all sorts of pro and con arguments.

Basically, it's a choice you'll have to make for
yourself, based on what you can glean from the soon to
start arguments... ;-)

So I went shopping, and the seller told me the CCD sensors on modern
DSLRs were already coated with an anti-UV layer, and UV filters were

Well, no they are *not* coated. But yes there is an
Anti-Aliasing filter in front of the sensor, and one
effect is that both Infra Red and Ultra Violet are
intentionally reduced at the sensor.

therefore useless, or recommended for film cameras only. I trusted him
and bought a simple lens protector.

That's the correct decision, assuming you actually want
to degrade your images with a filter that does nothing
in front of the lense...

A UV filter wouldn't do anything useful in comparison.

I could not find any information relevant to the existence of UV-filter
coatings on CCDs. Any definite answer ?

There are virtually always on going threads in the various
newsgroups on photography about exactly that. There are also
untold numbers of web sites that will give you information.

www.google.com is your friend...

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

Lorenzo Sandini wrote:
Hello,

First post from a DSLR newbie, please bear with me.

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a
Sigma 18-200 for convenience. A friend of mine suggested I buy some
Hoya
filters as well, at least a UV filter for taking photos in bright
sunshine. He insisted that I could keep it on all times as a
protector
as well, it wouldn't affect the quality of the pictures in other
conditions.

So I went shopping, and the seller told me the CCD sensors on modern
DSLRs were already coated with an anti-UV layer, and UV filters were
therefore useless, or recommended for film cameras only. I trusted
him
and bought a simple lens protector.

I could not find any information relevant to the existence of
UV-filter coatings on CCDs. Any definite answer ?

If you googling "uv photography" the third hit was
http://www.naturfotograf.com/UV_IR_rev00.html, which will tell you
more than you wanted to know about UV and digital cameras.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

Floyd L. Davidson wrote:
Lorenzo Sandini wrote:
First post from a DSLR newbie, please bear with me.

Bears are nasty animals, and if you have one with you,
you're due some real respect.

I wouldn't go out to the usenet without one.

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma

This is not a microscope, it's a camera. That is not an
objective, it's the freaking *lense*! :-)

Lens has always sounded like "lentil" (lens culinaris) to me, so I
prefer to use objective (as in "objektiivi" in finnish). But for my
first appearance in here I'll accept the criticism as contructive.

18-200 for convenience.

It's a good thing you got it for convenience, because
you don't exactly have the two highest quality lenses
that Nikon ever made... :-(

According to what I read here and there, I certainly agree, and I am
taking recommendations for my next lens (ooh look, I wrote lens). again,
I am only a beginner...

A friend of mine suggested I buy some Hoya
filters as well, at least a UV filter for taking photos in bright
sunshine.

At that point, you can begin to disregard everything he
ever says about photography. Smile, listen... and let
it all pass. Whatever a UV filter might be for, bright
sunshine isn't part of it!

Aaaah, friends. What would we do without 'em ? Well, next sunshine will
be in 6 months or so, so plenty of time to make my mind. (Greetings from
Finland btw)

He insisted that I could keep it on all times as a protector
as well, it wouldn't affect the quality of the pictures in other conditions.

Well, you _can_ keep it on at all times, and yes it will
act as a protector. Whether you need a protector for
the front of your lense is a question that will draw all
sorts of arguments both for and against. Generally, you
don't. But if you are taking pictures in a welding
shop, at the beach, or some other equally hostile place,
it might well be worth having a protective filter.

A welding shop would be an interesting place to take photos, thank you
for the recommendation. Now that I have a lens protector (see ? I wrote
lens again), I really need to find hostile places

long snip

Thank you for your answer, I'll probably keep the lens protector where
it is needed, and take photos without whenever I can. As for UV light,
I'll remember this the next time I'll climb the K2 or the Everest.

Lorenzo

"Lorenzo Sandini" wrote:

First post from a DSLR newbie, please bear with me.

Welcome aboard!

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma
18-200 for convenience. A friend of mine suggested I buy some Hoya filters
as well, at least a UV filter for taking photos in bright sunshine. He
insisted that I could keep it on all times as a protector as well, it
wouldn't affect the quality of the pictures in other conditions.

So I went shopping, and the seller told me the CCD sensors on modern DSLRs
were already coated with an anti-UV layer, and UV filters were therefore
useless, or recommended for film cameras only. I trusted him and bought a
simple lens protector.

The seller is more correct than your friend. 30 years ago, I wouldn't
have said that.

Like most of today's dSLR's, the D80 has built-in UV filtration. Fuji
briefly made a specialty dSLR that was UV and IR sensitive, and some
older dSLR's were more sensitive to UV, but for the vast majority of dSLR
owners a UV filter is only useful as a protector.

Most modern film is also UV insensitive. Unless you are using tungsten
balanced color film or traditional black and white film, you don't need
a UV filter with film.

Furthermore, both of your lenses also have coatings and optical cement
which block most UV. This is true of the vast majority of lenses made
in the last 25 years.

Using any filter can impact image quality. Every air-glass surface
results in some light loss and increased risk of flare. Unlike clear
protectors, UV filters also filter out some additional visible purple
and indigo light. You can see this by placing a UV filter on a bright
white sheet of paper.

If you use a top-quality multicoated UV filter like a Nikon L37c, under
many circumstances you will only detect the difference by "pixel
peeping" each shot and doing a side-by-side comparison. A cheap,
uncoated UV _or_ clear filter will cost you at least 9% of your light,
plus greatly increase the chance of flare.

I do own some very old lenses, and do use UV sensitive film at times.
As a result, I own B+W 010 MRC UV filters, but usually shoot without
a filter.

--
Michael Benveniste -- (Clarification required)
Cogito ergot sum. (I think I'm an hallucinogenic fungus.)

Lorenzo Sandini wrote:
[]
Lens has always sounded like "lentil" (lens culinaris) to me, so I
prefer to use objective (as in "objektiivi" in finnish). But for my
first appearance in here I'll accept the criticism as contructive.


I have no problems with the term objective.

David

"Floyd L. Davidson" wrote in message
...
Lorenzo Sandini wrote:
First post from a DSLR newbie, please bear with me.

Bears are nasty animals, and if you have one with you,
you're due some real respect.

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma

This is not a microscope, it's a camera. That is not an
objective, it's the freaking *lense*! :-)

Hmmm, you arrogant arsehole! The OP is in Finland, so English isn't his
first language. Objective is technically correct, as is lens. However lense
is not the common spelling of lens. It is sort of correct, but not the
accepted version. As for "freaking"

intr. & tr.v. freak·ing, Slang

To experience or cause to experience frightening hallucinations or feelings
of paranoia, especially as a result of taking a drug. Often used with out.
To behave or cause to behave irrationally and uncontrollably. Often used
with out.
To become or cause to become greatly excited or upset. Often used with out.

So how can a lens "freak out"???

I bet Lorenzo speaks better English that you speak Finnish! The Internet,
and usenet are global. What will you do next correct the 90% of the English
speaking World that uses the word colour, instead of the USA variant color?

Floyd L. Davidson wrote:
..

This is not a microscope, it's a camera. That is not an
objective, it's the freaking *lense*! :-)

..
In optics terminology the main imageforming lens of a camera is
frequently termed an "objective" lens. This differentiates it from any
lenses in the viewfinder, rangefinder, etc.

Lorenzo Sandini wrote:

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma
18-200 for convenience.

Convenience, yes. High quality ... not so much. If your glass
is good enough and fast enough for you, more power to you.

A friend of mine suggested I buy some Hoya
filters as well, at least a UV filter for taking photos in bright
sunshine.

Not needed. Digital cameras have white balance, and on Auto mode
it'll at best countercorrect your filter. (This may be useful
if you need to e.g. dampen an overabundance red light during
a concert, but you'll know when you'll be inthat situation.)

He insisted that I could keep it on all times as a protector
as well,

It's called a front cap, or (during shooting) a lens hood.

Unless it's flying mud, sand, sal****er and so on, then
you'll want a good, multi-coated protector. Why multicoated
and so on?
a) Each element in the optical path --- even air over longer
distances --- can and will degrade the image quality to some
degree.
b) digital sensors are good mirrors. There's a reason why
lenses with a mostly protective first element don't have a
flat glass there (this is corrected by the other elements) ---
reflections from the sensor back on the sensor aren't good for
image quality. Well-coated protectors reflect much less light.

Especially in high contrast images you'll probably see
reflections from the brighter parts in the darker parts.

c) Light reaching the protector at an angle should not be
'smeared' over the whole image, that reduces contrast.
Well-coated protectors do have less effect in that
situation.

it wouldn't affect the quality of the pictures in other conditions.

A lens hood will improve your images, as stray light can be
prevented from reaching the lens. (Of course, it's somewhat
complicated to get a good lens hood for a superzoom.)

-Wolfgang

On Wed, 22 Oct 2008 03:14:23 -0800, Floyd L. Davidson wrote:

Lorenzo Sandini wrote:
First post from a DSLR newbie, please bear with me.

Bears are nasty animals, and if you have one with you,
you're due some real respect.

I got a Nikon D80 with a Nikkor 18-55VR objective, and I bought a Sigma

This is not a microscope, it's a camera. That is not an
objective, it's the freaking *lense*! :-)

18-200 for convenience.

It's a good thing you got it for convenience, because
you don't exactly have the two highest quality lenses
that Nikon ever made... :-(

The bear has left the room, replaced by your freaking *bull*!

Did you notice that what you quoted has the OP saying that the
18-200 lens was made by Sigma, not Nikon? But in your never ending
quest to find ways to provide help that is larded with smugness,
condescension and superciliousness, you've once again attained your
lens . . . uh, objective.


www.google.com is your friend...

Well, yes, if one knows how to properly use it, and knows enough
to be able to filter the nonsense it can sometimes dredge up. Many
agree with your advice, but several (found on the first google
search results page) didn't. Here's one :

Graphyphoto.com | Photography & Methods
Fotodiox UV Filter Image Results (click on the photo for a 100% crop) ...
Labels : UV Filters Effects on Photos Benefits and the Cost to Contrast and Color ...

http://www.graphyphoto.com/labels/UV...20Color.htm l

Google can indeed be a friend, or rather, point you towards
useful, friendly advice. But it also does little or nothing to
shield you from false friends. The OP did himself a favor by asking
his question here instead of first trying Google, since this smaller
community does a good job of 'filtering' out those false friends
that would intentionally or unwittingly provide bogus information.